The present disclosure is related to prosthetic heart valve replacement, and more particularly to devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves.
Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.
Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are at least two types of stents on which collapsible valves are mounted: self-expanding stents and balloon-expandable stents. To place a collapsible valve into a delivery apparatus and ultimately into a patient, the valve is first collapsed or crimped to reduce its circumferential size. When a collapsed valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be released from the delivery apparatus and re-expanded to full operating size.
Despite the various improvements that have been made to the collapsible prosthetic heart valve delivery process, conventional delivery devices, systems, and methods suffer from some shortcomings. For example, the self-expanding collapsible valve may include retainers that are inserted into corresponding retainer slots in a catheter to hold the valve in a desired position and/or orientation. During deployment of the self-expanding valve into the desired area (e.g., the aortic valve annulus), forces applied on the stent may restrict the ability of the stent retainers to fully release from the corresponding retainer slots of the catheter. There therefore is a need for further improvements to the devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves.